The preparation of hydrocarbyl phenates and hydrocarbyl salicylates is well known in the art.
U.S. Pat. No. 3,036,971 discloses preparing detergent-dispersant additives based on sulfurized alkylphenates of high basicity alkaline earth metals. These additives are prepared by sulfurization of an alkylphenol, neutralization of the sulfurized alkylphenol with an alkaline earth metal base, then super-alkalization by carbonation of the alkaline earth metal base dispersed in the sulfurized alkylphenate.
U.S. Pat. No. 3,410,798 discloses basic metal salts of phenol or salicylic acid sulfides prepared by reacting a phenol or salicylic acid, or a slat thereof, with sulfur and an alkaline earth base at a temperature of about 150-200° C., in the presence of a carboxylic acid or salt thereof and a polyalkylene glycol or alkylene or polyalkylene glycol alkyl ether. The products are useful as detergent additives for lubricants.
U.S. Pat. No. 5,035,816 discloses a process for preparing alkylsalicylate superalkalinized detergent-dispersant lubricating oil additives: (a) by the acid catalyzed neutralization of C12-C30 alkylphenol with alkaline earth base in the presence of an azeotropic solvent for the water of reaction; (b) by the carboxylation of the first product with CO2 to partially convert the alkylphenate to alkylsalicylate; and (c) by sulfurization-superalkalinization of the product in the presence of sulfur, alkaline earth base, azeotropic solvent and added CO2 superalkalized detergent-dispersant additives based on alkylphenates and alkylsalicylates.
U.S. Pat. No. 6,291,408 discloses dispersant detergent additives for lubricating oils prepared by neutralization, carboxylation, sulfurization-overalkalinization, carbonation, distillation, filtering and degassing from alkyl phenols containing 35-85% by weight of linear alkyl substituents. The process does not require, during the neutralizing phase, the presence of a third solvent, which, by forming an azeotropic mixture with water promote the elimination of water arising from the neutralizing reaction. The additives of the invention have improved stability to hydrolysis and improved dispersion properties, improved compatibility and improved foaming properties.
U.S. Pat. Nos. 6,162,770 and 6,262,001 teach an unsulfurized, alkali metal-free, detergent-dispersant composition having from 40% to 60% alkylphenol, from 10% to 40% alkaline earth alkylphenate, and from 20% to 40% alkaline earth single-aromatic-ring alkylsalicylate, and a process for preparing the same. This composition may have an alkaline earth double-aromatic-ring alkylsalicylate as long as the mole ratio of single-ring alkylsalicylate to double-aromatic-ring alkylsalicylate is at least 8:1. This composition may be produced by the three-step process involving neutralization of alkylphenols, carboxylation of the resulting alkylphenate, and filtration of the product of the carboxylation step. The detergent-dispersant produced by the method can be used in an engine lubricating composition to improve antioxidant properties, high temperature deposit control, and black sludge control.
The addition of aliphatic carboxylic acids during the preparation of lubricating oil detergents is known. The resulting detergents can be referred to as carboxylic acid modified detergents and a variety of such detergents are known. The incorporation of aliphatic carboxylic acids into such detergents is known to modify their physical and/or performance properties. The most common physical modification observed by the incorporation of fatty acids into detergents, which is also the most common reason for performing this modification, is an increase in the TBN of the detergent without deleteriously increasing the viscosity of the product to an unacceptable level.
U.S. Pat. No. 3,493,516 discloses that the alkalinity value in the preparation of overbased phenates is enhanced by the addition of aliphatic carboxylic acids of from 1 to 6 carbon atoms to the reaction mixture during the preparation of the overbased alkyl phenate. Adding small amounts of low molecular weight carboxylic acids during the preparation of overbased alkylphenates, greater than 10 percent enhancements in the amount of calcium is obtained. The enhanced amount of calcium provides greater neutralization capability and superior protection in the engine against sludge formation. Despite the great enhancement in calcium content, the viscosity remains sufficiently low to provide a tractable product.
European Patent application No. 385,616 discloses the use of fatty acids in the production of overbased phenates from alkylphenols or phenates with increased TBN's and acceptable viscosity.
European Patent application No. 351,052 discloses the use of long chain carboxylic acids in the production of overbased salicylate detergents with TBN's greater than 300 and viscosity's less than 1000 cSt at 100° C.
European Patent application No. 347,104 discloses the use of long chain carboxylic acids to produce overbased carboxylic modified low overbased sulphonates and/or phenates and/or salicylate detergents with improved deposit forming properties.
European Patent application No. 347,103 discloses a process for producing carboxylic acid modified overbased phenates with TBN's greater than 300 and viscosities less than 1000 cSt at 100° C. starting from a phenate.
European Patent application No. 351,053 discloses the production of carboxylic acid modified overbased sulphonates with TBN's greater than 350 and viscosities less than 1000 cSt at 100° C. that have better filtration processing characteristics.
U.S. Pat. No. 5,716,914 discloses a process for producing a carboxylic acid modified overbased phenates with TBN's greater than 300 and viscosities less than 1000 cSt at 100° C.
U.S. Pat. No. 5,069,804 discloses improved stability of overbased phenates, particularly when formulated with overbased sulphonates, as well as improved foaming tendency and viscosity is obtained by treating the overbased phenate, either during or subsequent to the overbasing process, with from 0.1 to 10 wt %, preferably 2 to 6 wt %, of a carboxylic acid with a C10 to C24 unbranched segment, e.g. behenic acid.
U.S. Pat. No. 5,714,443 discloses an additive concentrate suitable for incorporation into a into a finished lubricating oil composition, the additive concentrate comprising: (a) a lubricating oil; (b) a lubricating oil soluble sulphurised alkaline earth metal hydrocarbyl phenate modified by incorporation of from greater than 2 to 35% by weight based on the weight of the composition of either (i) at least one carboxylic acid having formula (I), wherein R is C10 to C24 alkyl or alkenyl group and R1 is either hydrogen, a C1 to C4 alkyl group or a —CH2—COOH group, or an anhydride, acid chloride or ester thereof or (ii) a di- or polycarboxylic acid containing from 36 to 100 carbon atoms or an anhydride, acid chloride or ester thereof, the composition having a TBN greater than 300.
U.S. Pat. No. 5,433,871 discloses a process for the production of carboxylic acid modified overbased mixed detergents (phenate and/or salicylate and/or napthenate and/or sulfonate) with TBN's greater than 300 while retaining an acceptable viscosity.
U.S. Pat. No. 6,348,438 discloses an overbased alkaline earth metal single-aromatic ring hydrocarbyl salicylate-carboxylate is produced by overbasing a mixture of a single-aromatic ring hydrocarbyl salicylate, at least one solvent, a metal hydroxide, and an alkyl polyhydric alcohol alkaline earth metal hydroxide, by contacting that mixture with carbon dioxide under overbasing reaction conditions. The alkyl group of the alkyl polyhydric alcohol has from one to five carbon atoms. The overbased metal single-aromatic ring hydrocarbyl salicylate is treated, before, during, or subsequent to overbasing, with a long-chain carboxylic acid to form a single-aromatic ring hydrocarbyl salicylate-carboxylate.